Mask to mask resuscitator



y 19, 1959 E. 5. BROWN ETAL 2,887,105

MASK TO MASK RESUSCITATOR 2 Sheets-Sheet 1 Filed March 12, 1958 INVENTORS E Iwyn S. Brown David X Cooper James 0. Elam Richard J. Johns I B!" ATTORNEY May 19159 E. 5. BROWN ETAL 2,887,l0

} msx T0 MASK RESUSCITATOR 2 Sheets-Sheet 2 Filed March 12, 1958 nvwgvrons yn S. Brown David X Coopgr James 0. Elam v Richard J. Jalm; BY F I ATTORNEY United States Patent MAUSK T0 MASK RESUSCITATOR Elwyn S. Brown, Elma N.Y., David Y. "Cooper, Wayne,

; Application March 12, 1958, Serial No. 721,073

. 2 Claims. 01. 128-29) The invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment to us of any royalty thereon.

. This invention relates to a resuscitator particularly adapted for use in a contaminated atmosphere.

n. the treatment of victims of poison gases, particularly to so-called nerve gases, it is frequently necessary to resort to some type of artificial respiration or resuscitation. Sincethe resuscitation must be carried out promptly, the method must be such that it can be carried out in a contaminated atmosphere while both the casualty and the operator are protected. The apparatus employed should be light, simple, and easily transported.

One previously known method is termed mouth-toniouth resuscitation. It consists in the operator blowing exhaled air into the mouth of the casualty. Our apparatus makes possible a variation of this method, which we term mask-to-mas resuscitation. The operator inhales through a canister and gas mask. He then exhales into the lungs of the patient. Finally, the patient exhales to the atmosphere. Our apparatus makes it possible for the operator to carry out this cycle for extended periods of time and-ensures that the casualty receives air of adequate oxygen content.

Inthe drawing, Figs. 1, 2, and 3 are external views, schematic in character, showing the three steps of a cycle employing a simple embodiment of our invention.

Fig. 4 is a view partially in plan and partially in section showing another embodiment of our invention.

The apparatus of Figs 1-3 comprises an operators mask 1, a casualtys mask 3 and a flexible connecting tube 5. Between the tube 5 and the casualtys mask 3 is a T-connection 7 having an outlet 9, which contains a conventional one-way outlet valve of the type normally used in gas masks.

The operators mask 1 is a standard gas mask including the usual canister 11 which is, however, closed by a plug 13. It also includes the usual outlet tube 15. The usual ouflet valve is, however, removed and the tube 5 connected in its place. The casualtys mask 3 is likewise a standard gas mask from which the outlet valve has been removed and replaced by the T-connection 7. Mask 3 includes the usual canister 17, which is left open. Canisters 3 and 11 are associated with the usual one-way inlet valves, which may either be part of the canister or part of the mask.

Figure 1 shows the first step of a cycle of operation. The operator inhales deeply through canister 17, casualtys mask 3, T-connection 7, tube 5 and operators mask 1. The valve in outlet 9 closes. At the end of this step the entire system is filled with fresh, purified air.

In the second step, shown in Fig. 2, the operator closes outlet 9 with his hand and exhales. This forces the fresh air filling the system into the casualtys lungs, followed by a part of the air exhaled by the operator. At

'ice

In the third step, shown in Fig. 3, the operator removes his hand from outlet 9 and holds his breath. The elasticity of the casualtys lungs causes him to exhale through outline 9.

The step of Fig. 1 is then repeated. It will be noted that the operator first rebreathes the exhaled air, which fills the system, followed by fresh air, and the cycle continues as before.

An important feature of our invention is the fact that the operative canister, 17, is at the casualtys mask. One of the problems involved in mouth-to-mouth or mask-tomask resuscitation is hyperventilation of the operator, who must breath much more deeply than normal.

If the canister 11 is used as the source of the operators air, so that only fresh air is inhaled, the carbon dioxide content of the lungs is lowered to the point where dizziness and other symptoms of hyperventilation occur,

making it difiicult or impossible for the operator to continue the resuscitation for the requisite length of time. When the operative canister is at the casualtys mask, the resultant rebreathing of exhaled air by the operator serves to keep the carbon dioxide concentration in his lungs at a value such that the effects of hyperventilation are minimised, making it possible to maintain the resuscitation for long periods.

The location of the operative canister also benefits the casualty, whose breathing has stopped and who is suffering from suffocation. It is desirable that he receive as much oxygen as possible. If canister 11 were the operative canister, the casualty would receive only exhaled air. With our arrangement, he receives fresh air as Well.

The T-connection 7 with its outlet 9 is located adjacent to the casualtys mask in order that the resistance may be as small as possible when the casualty exhales and also in order to cause the operator to inhale a minimum quantity of the casualtys exhaled air.

While the canister 11 is inoperative in the combination described, it is desirable that it be present. The flexible tube 5 can be disconnected from outlet tube 15 and the conventional outlet valve replaced. The operator can the end of this step, the system is filled with the operators exhaled air and the casualtys lungs are inflated.

then remove plug 11 and utilize mask 1 as a conventional gas mask until it is necessary to treat another casualty.

Figure 4 shows second embodiment of our invention which employs an automatic valve instead of the T connection 7 of Figures 1-3, which has only an outlet valve.

This second embodiment includes an operators mask 101 and a casualtys mask 103. Between the masks is flexible connecting tube 105. The operators mask 101 includes the canister 111 which is closed during the resuscitation cycle by a plug 113. The casualtys mask includes a canister 117 which is inoperative during the resuscitation cycle but which is preferably left open for reasons which will be explained later. The operators mask 101 includes the usual outlet tube 115 from which the usual outlet valve has been removed. The flexible tube is preferably connected to outlet tube by a quick-disconnect coupling. The mask 103 also includes outlet tube 116 from which the outlet valve has been removed.

The apparatus thus far defined is the same as that of Figures 1-3. In this embodiment, however, we include an automatic valve indicated at 121 and a resuscitator canister 123 which provide a more convenient means of carrying out the resuscitation cycle. Resuscitator canister 123 is mounted on a side arm 125 of a T-connection 127, which is connected to flexible tube 105 and automatic valve 121. One way inlet valve 129 may be located either in the T-connection as shown or in canister 123.

Valve 121 will now be described. This valve per se is not our invention but was obtained from the I. H. Emerson Resuscitator Company.

The valve includes an outer housing 131 and an inner tube 133. The inner tube is provided with an annular shoulder 135 which fits inside outer housing 131. Within outer housing is acne-way inlet valve 137 and a valve leaflet 139 which is movable between the positions shown in solid and broken lines. Casualtys side arm connection 141 and outlet side arm connection 143 are also joined to outer housing 131. The various elements of valve 131 define several chambers, as follows: An inlet chamber 145 to the left of inlet valve 137, a central chamber 147 formed by inlet tube 133, inlet valve 137 and outer housing 131, outlet chamber 149 formed by inner tube 133, shoulder 135, outer housing 131 and outlet side arm connection 143, and a control chamber 151 lying between the right hand end of inner tube 133 and the end closure 153. A pressure-equalizing tube 155 connects inlet chamber 145 with end closure 153.

The masks 101 and 103 are preferably provided with inwardly folded edges 157 which serve to prevent leakage around the edges when superatmospheric pressure prevails in the masks.

The cycle of operations is as follows:

A. The operator inhales.Valve 137 closes and valve 129 opens. Outside air is drawn in through canister 123 and thus purified. The purified air fills tube 105 and mask 101 and enters the operators lungs. At the end of this step the tube 105 is filled with freshly purified air.

B. The operator exhales.Valve 129 closes and valve 137 opens. Also, air flows through pressure equalizing tube 155, thus equalizing the pressure in inlet chamber 145 and control chamber 151. This pressure is above atmospheric. The pressure in outlet chamber 149 is atmospheric. Only a portion of the left face of valve leaflet 139 is exposed to the pressure of central chamber 147 while the entire right face is exposed to the pressure of control chamber 151. Valve disk 139 is therefore held in the full line position, closing the end of inner tube 133. As the operator continues to exhale, air is forced through casualty side arm connection 141 into mask 103, inflating the casualtys lungs.

C. The operator again inhales.This lowers the pressure in inlet chamber 145 below atmospheric. The valve 137 closes. The casualty exhales due to the elasticity of his lungs. Due to tube 155 the pressure on the right hand face of valve leaflet 139 is less than that on the left face. Valve leaflet 139 therefore moves to the right toward the broken lines position, so that control chamber 151 con- 1 nects central chamber 147 with outlet chamber 149. The casualty therefore exhales to the atmosphere.

At the end of step B, hose was filled with air exhaled by the operator. During step C he therefore first inhales this exhaled air, followed by fresh purified air.

The cycleof steps A, B, and C is then-repeated until the casualty begins to breath again. Canister 117 now.

disconnected from outlet tube and the under valve replaced. Mask 101will then function in the normalf manner.

While we have shown two embodiment of our invention, it will be apparent that further modifications 'are possible. In particular, other valves performing thesame function may be substituted for valve 121. For example, that shown in. Reissue Patent No. 24,193 (reissue "of;

Patent No. 2,428,451) may be employed.

We therefore wish our invention to be limited solely by the scope of the appended claims.

We claim:

'1. A mask-'to-mask resuscitator comprising an 'operators gas mask having no operative inlet for air, a

casualtys gas mask having an air inlet adjacent thereto,

a tube connecting said masks, and an outletto the atmosphere connected to said tube adjacent said casualtys mask.

2. A mask-to-mask resuscitator comprising an operators gas mask having no operative inlet for air, a.

casualtys gas mask, air inlet means adjacent saidcasual' tys mask and comprising an air-purifying canister, a tube connecting said masks, and an outletconnected to said" tube adjacent said casualtys mask, said outletbeingfso constructed and arranged that it may be-closed when t'h'e operator exhales and opened when the casualty'e'xhales.

References Cited in the file of this patent UNITED STATES PATENTS 2,280,050 Alexander et a1. Apr. 21', '1942 i 

